<!DOCTYPE html>
<html lang="zh-CN">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      div {
        width: auto;
        height: 100px;
        line-height: 100px;
        background-color: red;
        font-size: 20px;
      }
      div > span {
        vertical-align: middle;
        /* background: green; */
      }
    </style>
  </head>
  <body>
    <div>
      vertical-align: 设置行内元素的垂直对齐方式x <span>备注：</span>值：top
      middle bottom baseline
    </div>
  </body>
</html>
